SAS was the first airline to introduce a polar route in 1957 to avoid Soviet airspace, making a stop in Alaska on its way to Japan.[1]
[1] https://airwaysmag.com/today-in-aviation/worlds-first-com-tr...
[1] https://airwaysmag.com/today-in-aviation/worlds-first-com-tr...
Flying from CPH to HND via Alaska adds almost 2300 miles vs flying direct over Russia:
[1] https://www.primidi.com/scandinavian_airlines/history/trans_...
Not to mention, historically people who don't have to often avoid connecting in the US because I think there is / was an extra visa burden, even if it's just for transit. I think many people might avoid a route that makes them enter the US, though mayb things have changed and it's less of hassle.
http://www.gcmap.com/mapui?P=cph-ist-gyd-ala-pek-hnd;+cph-an...
That route also goes through the PRC which was closed for a few decades to outside airplanes as well. And some of the other countries on the map were part of the USSR as well.
That's why KLM fitted its polar-route aircraft with "Polar survival kits", including rifles to shoot polar bears if needed (for defence or calories, it's not clear): https://2.bp.blogspot.com/-arvz6OHAQO0/UHxrLfdrLII/AAAAAAAAC...
https://www.ar15.com/forums/ar-15/KLM-Arctic-Survival-Kit/12...
Also, I recall reading that for Easter Island, only one plane can be inbound during a given window, because it is remote enough that there is nowhere to divert to. But you'd have to check to make sure I'm remembering correctly
This is called "Intermediate Stop Operations". Of course, there are other costs beyond fuel (landing costs, staffing costs, etc.), but sometimes you can make this an advantage (e.g. staff always sleeps at home base each night).
> In some studies it was found that fuel savings are in the order of 13–23 % (the longer the mission, the more fuel could be saved) for missions with a single stopover if aircraft are used that are optimized for shorter ranges
https://elib.dlr.de/102479/1/metz__The_Implications_of_Inter...
First your generally going out of the way to stop at an airport which means a longer trip, plus you need to climb back to altitude which means lower efficiency. Landings and takeoffs are harder on many systems which means more maticance. Time a major factor as not only are aircraft doing fewer routes passengers are also waiting around. Safety is another issue for adding stops, landing and takeoffs are much higher risk. Etc
It can be a net benefit, but normally your much better served to make every stop a significant destination rather than just being for fuel.
That's where it can become more viable: When you go A->B->C instead of A->C, you have two more origin:destination pairs that you sell tickets for, depending on (?uhhhh, 5th?) freedom rights.
As much as people hate it (especially if someone else is paying the fare), I think long-haul’s days aren’t looking great. As fuel/biofuel becomes a bigger $ proportion of tickets, multiple medium-haul hops is going to become the way.
I think most expensive would still be gaining altitude - but I got down-voted so might be that my understanding of this is not that good.
In flight refueling might be the way to go, but then keeping the fuel plane up also takes fuel.
Anchorage is already one one of the busiest airports in the world for cargo. During the beginning of the pandemic, it became the busiest airport in the world for that reason (while people weren't flying, cargo still needed to be flown).
That video goes into a bit on the importance of its airport.
By using a stopover, they are able to cut down on total fuel needed to be carried which in turn raises the amount of freight that they can carry.
As others have mentioned, Anchorage is a big cargo airport, and the fuel savings are one of the reasons.